“…Linearity is initially acquired for smaller ranges and progressively, with age and increasing number knowledge, linearity is extended to larger ranges (Berteletti et al, 2010; Siegler and Booth, 2004; Siegler et al, 2009). Performance on the NL task correlates with other estimation tasks (Booth & Siegler, 2006; Laski & Siegler, 2007), improves following interventions on children's linear and cardinal understanding of the numerical sequence (Ramani and Siegler, 2008; Siegler and Ramani, 2008), and is correlated with and is predictive of arithmetic learning and mathematical achievement (Booth & Siegler, 2008; Link, Nuerk, & Moeller, 2014; Linsen, Verschaffel, Reynvoet, & De Smedt, 2014; Ostergren & Träff, 2013; Sasanguie, Göbel, Moll, Smets, & Reynvoet, 2013; Schneider, Grabner, & Paetsch, 2009). Performance is also impaired or delayed in children with math learning difficulty (Geary et al, 2008; Landerl, 2013).…”